This alkaline 9V battery has a capacity of 500mAh and is suitable for powering the Arduino. The blister pack contains 6x 9V batteries.
Specifications
Nom. voltage: 9V
Type. capacity: 500 mAh
IEC: 6LR61
Format: 9V
Types: E-block
Dimensions: 26.2 x 17.5 x 48.5 mm
Packaging: blister